What new idea about succession came from studying the eruptions of Mount Saint Helens?

A. Succession theory predicted exactly how Mount Saint Helens would recover.

B. Succession is a steady progression that, once started, goes to a predictable conclusion.

C. Only invading species from outside the disturbed area participate in succession.

D. Succession involves both biological legacies and invading species.

Mount Saint Helens volcanic eruptions was an example of ecological succession after a catastrophic event that occurred in 1980. Charlie Crisafulli was a ecologists who visited the volcanic site along with his colleagues to collect ecological data. He noted the development of ecological relationships across the volcanic landmass. He documented the types, amounts and distribution of surviving organisms, which further took forward the responsibility of colonization in a destructed habitat. This was the example of secondary succession in which succession occurs after the natural calamity has disturbed the natural ecosystem. The species living there were able to colonize the landmass again after volcanic eruption. Therefore, the succession theory predicted exactly how Mount Saint Helens would recover.